1. Field of the Invention
This invention relates to a printer ink cartridge which is removably loaded in an ink jet printer and an ink cartridge device including the same.
2. Prior Art
FIGS. 11A and 11B show a conventional ink cartridge. The ink cartridge 50 is comprised of a cartridge body 52 having three (YMC) ink reservoirs 51 for holding yellow ink, magenta ink and cyan ink, a delivery port-sealing film 54 for covering ink delivery ports 53 of the cartridge body 52, and an air inlet port-sealing film 57 for covering ink-charging ports 55 and air inlet ports 56 of the cartridge body 52. The three ink-charging ports 55 and three air inlet ports 56 are formed to open in a top surface of the cartridge body 52, and further, meandering air inlet grooves 58 continuous with the respective air inlet ports 56 are formed in the top surface. The air inlet grooves 58 each have its open side (opening) covered with the air inlet port-sealing film 57 (attached to the top surface of the cartridge body 52 by hot-melt bonding) to thereby form air inlet passages 59 in the air inlet grooves 58.
In the above state, the ink cartridge 50 is enclosed in an aluminum package, not shown, for shipment. Ink in the cartridge body 52 is made liable to degradation by exposure to air. To avoid this inconvenience, the ink cartridge 50 has the ink delivery ports 53 thereof sealed (by hot-melt bonding) by the delivery port-sealing film 54, and then, after being charged with ink from the ink-charging ports 55 in a vacuum chamber, the ink-charging ports 55 and air inlet ports 56 are sealed (by hot-melt bonding) by the air inlet port-sealing film 57. In this state, the ink cartridge 50 is vacuum-packed in an aluminum package for supply to the user.
When the ink cartridge 50 is used by the user, first, the aluminum package is unsealed to take out the ink cartridge 50, and thereafter, part (peel-off portion 57b) of the air inlet port-sealing film 57 is peeled off, and the air inlet ports 56 (more accurately, upstream ends 59a of the air inlet passages 59 continuous with the air inlet ports 56) are opened to the atmosphere, while the delivery port-sealing film 54 is peeled off to open the ink delivery ports 53. In this state, the ink cartridge 50 is loaded in a printer.
The conventional ink cartridge having the above construction suffers from the problem that when the delivery port-sealing film is removed (peeled) off from the cartridge body, ink held in the vicinity of the ink delivery ports may be spilled and ink adhering to the delivery port-sealing film, particularly, a delivery port-sealing portion thereof may touch the user's hand, so that the user's hand, a desk, or the like can be stained with the ink. Further, there is a fear that the user forgets to peel off the delivery port-sealing film and loads the ink cartridge still covered therewith in the printer. Further, the conventional ink cartridge has the inconvenience that since the inside of the cartridge body is in vacuo, air can be mixed into ink to cause a faulty printing operation, unless the films are peeled off in order of the air inlet port-sealing film, first, and then the delivery port-sealing film according to an instruction manual of the ink cartridge supplied to the user.
The meandering portions of the three air inlet passages 59 are formed within an area of two thirds of the top surface of the cartridge body 52, while the upstream ends 59a of the air inlet passages 59 extend within an area of the other one third of the same. The air inlet port-sealing film 57 has a non-peel-off portion 57a which covers substantially the whole area of the two thirds of the top surface of the cartridge body 52 to close the meandering portions and should not be torn off and a peel-off portion 57b which covers a major portion of the remaining area of the other one third to close the upstream ends 59a. The non-peel-off portion 57a and the peel-off portion 57b are connected by a narrow connecting portion crossing over starting portions of the upstream ends 59a of the air inlet passages 59 (as a result, the whole air inlet passages 59 including the upstream ends 59a is closed). From the peel-off portion 57b protrudes a peeling operation portion 57c for use in tearing off the peel-off portion. The user holds the peeling operation portion 57c between the finger and thumb, and then tears off the peel-off portion 57b, thereby opening the upstream ends 59a of the air inlet passages 59 to the atmosphere. The user further tears off the delivery port-sealing film 54 to open the ink delivery ports 53, and then loads the ink cartridge 50 in this state in the printer.
The meandering air inlet passages 59 permit air to be supplied to each ink reservoir 51 by the amount corresponding to an amount of ink used or delivered from its ink delivery port 53, while minimizing vaporization of water content of the ink. To use the ink cartridge, therefore, the peel-off portion 57b is torn off, thereby opening the upstream ends 59a to the atmosphere. When the ink cartridge is shipped or before it is used, however, the upstream ends 59a are required to be closed by the air inlet port-sealing film 57. Therefore, to maintain the closed state of the upstream ends 59a, perforated lines or the like for guiding a peeling operation are not formed in the narrow connecting portion crossing over the starting portions of upstream ends 59a of the air inlet passages 59.
In the case of such a conventional ink cartridge, when the peel-off portion 57b of the air inlet port-sealing film 57 is torn off, if the user applies a peeling force in a wrong direction, cutting lines are caused to be displaced particularly at the narrow connecting portion crossing the starting portions of the upstream ends of the air inlet passages, resulting in the peeling of part of the non-peel-off portion (shortened air inlet passages). Or inversely, depending on the arrangement of the three upstream ends, portions to be peeled off cannot be properly peeled off (to cause faulty opening of the air inlet passages). Needless to say, if the upstream ends 59a of the air inlet passages 59 are formed in a sufficiently wide area, it is possible to avoid the above inconveniences, unless an extremely erroneous peeling operation is carried out. In this case, however, an area for forming the meandering portions of the air inlet passages is necessarily made small, which makes it impossible to form the air inlet passages such that they have sufficient lengths.